Speaker
Description
This work focuses on the spatial and temporal characterization of two halogen lamps, measured experimentally using appropriate instrumentation: an infrared photodiode at the end of a robotic arm, and electrical current and voltage sensors placed across the terminals of the halogen lamp generator. The evaluation of the electrical power consumed, and the spatial and temporal distribution of the optical flux emitted by the lamps, allows for a systems-based modeling of the entire excitation chain. The electrical resistance of the tungsten filament, which depends on its temperature, is modeled analytically, and its mass and thermal inertia are also estimated through the generation of various waveforms (variable-frequency sinusoidal waves and square waves). Finally, an electrical and thermal transfer function associated with the generator and the tungsten filament of the lamps is proposed. The transfer function, a first-order low-pass type, demonstrates the limitation of halogen lamps in generating thermal frequencies higher than a few Hz. This work proposes a method for correcting these artifacts for applications involving the evaluation of thin materials or the characterization of the axial thermal diffusivity of materials. This offers prospects for achieving lighting with faster time constants.
